Toothpaste is a complex and homogeneously distributed mixture of various ingredients, forming a suspension system where insoluble solid powders are dispersed in a colloid.
It is generally composed of the following raw materials: abrasive agent, humectant, thickening agent, foaming agent, flavour, taste modifying agent, appearance modifying agent, preservative agent, buffering agent, antioxidants, functional agent, toothpaste water, and other components.
The specific composition is as follows.
1. Abrasive agent
Abrasives are solid ingredients in toothpaste that work in conjunction with a toothbrush to remove soft plaque from the tooth surface and reduce external substances such as stains, dental plaque, and calculus.
Abrasives are a primary component of toothpaste and are typically water-insoluble powdered solids with moderate particle size and texture that do not damage tooth enamel or dentin. Common raw materials used as abrasives in toothpaste include natural calcium carbonate, dicalcium phosphate dihydrate, hydrated silica (silicon dioxide), light calcium carbonate, aluminum hydroxide, and anhydrous dicalcium phosphate.
2. Humectant
Humectants are essential ingredients in toothpaste that help retain moisture, prevent the paste from hardening, and give it a smooth, pliable texture, making it easy to squeeze from the tube.
Humectants are generally polyol substances that maintain the paste’s body and flow. By retaining moisture, they ensure the paste remains soft and does not dry out, preventing separation of the solid and liquid phases during storage, especially in cold conditions. They can help the toothpaste maintain its fluidity and reduce the freezing point, preventing the paste from becoming dry and brittle. They prevent the paste from separating after freezing and thawing, ensuring the paste remains homogeneous and easy to dispense.
Commonly used humectants include glycerin, sorbitol, propylene glycol, and polyethylene glycol.
3. Thickening agent
Thickening agents, also known as binders, are added to toothpaste to increase its viscosity, create a stable gel-like consistency, and prevent the separation of solid and liquid components.
Thickening agents in toothpaste are generally divided into two main types: one type includes organic natural gums such as xanthan gum and carrageenan; another type includes organic synthetic gums such as carboxymethyl cellulose (CMC) and hydroxyethyl cellulose; and there is also a type of inorganic minerals such as hydrated silica and magnesium aluminum silicate.
4. Foaming agent
Foaming agents (surfactants) are added to toothpaste to reduce surface tension, enabling the paste to foam, emulsify, and penetrate, thereby aiding in the cleaning process.
Foaming agents are a primary component of toothpaste and are typically safe surfactants with small molecular size and rich foam production. They can make the toothbrush and teeth easier to wet, allowing the paste to spread throughout the mouth and reach all areas, thereby achieving the goal of cleaning the oral cavity. Common foaming agents include sodium lauryl sulfate (sodium dodecyl sulfate) and sodium lauroyl sarcosinate.
5. Flavor
Flavors are derived from natural plant essences, with both natural and synthetic flavors blended to create a variety of tastes.
Flavors are a primary component of toothpaste and generally comply with food hygiene standards for at least ten types of raw materials used to control the flavor, providing a refreshing and clean sensation, masking the taste of unpleasant flavors in the toothpaste base, and ensuring the stability of the final product. Toothpaste flavors are available in hundreds of varieties, with popular ones including peppermint, spearmint, and wintergreen.
6. Taste modifying agent
Taste modifiers are used to improve or mask undesirable flavors in the toothpaste base, making the product more palatable. The main components of taste modifiers in toothpaste are usually sweeteners and flavor enhancers.
Taste modifiers in toothpaste are generally composed of sweeteners such as saccharin, xylitol, and sucralose, as well as flavor enhancers commonly used in food such as sodium glycyrrhizinate.
7. Appearance modifying agent
Appearance modifiers are used to create a visually appealing product and enhance its perceived effectiveness. Currently, there are several types of colorants used in toothpaste, including natural pigments (such as chlorophyll) and synthetic dyes (such as titanium dioxide CI 77891, red CI 16185, yellow CI 19140, blue CI 42090). When using colorants, they must comply with national standards and not compromise the product’s stability or anti-plaque properties. The colorants used must meet national standards and should not affect the quality of the toothpaste, with good light-fastness.
Colored particles can be used in toothpaste to create a unique visual effect and distinctive feel, requiring compliance with national standards. The degree to which they affect the tooth mass production should not exceed the limit.
8. Preservative agent
Preservatives are used to prevent microbial contamination and spoilage of the toothpaste during its shelf life.
Toothpaste contains many organic compounds and moisture, making it susceptible to microbial growth. The selection of preservatives requires microbiological challenge testing to determine the final preservative. Common preservatives used in toothpaste include methylparaben and propylparaben, as well as other ingredients such as sodium benzoate, potassium sorbate, and monofluorophosphate.
9. Buffering agent
Buffering agents are used to maintain a stable pH in the toothpaste, preventing pH changes that could be caused by the decomposition of abrasives, which might lead to a gassy or gritty product.
Buffering agents must be properly formulated for the specific needs. Common buffering agents used in toothpaste include sodium pyrophosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium carbonate, and sodium bicarbonate. When used together with abrasives such as dicalcium phosphate, buffering agents like sodium pyrophosphate and sodium monofluorophosphate can have a synergistic buffering effect.
10. Antioxidants
Antioxidants are used to prevent oxidative degradation of certain ingredients, which can cause discoloration and reduce the stability of the toothpaste.
Antioxidants must be properly formulated for the specific needs. Antioxidants commonly used in toothpaste include butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), erythorbic acid, vitamin C, and vitamin E.
11. Functional agent
Functional agents are added to provide specific therapeutic benefits beyond basic cleaning. These agents must be safe for human use, have a scientific basis for their mechanism of action, and be approved by regulatory authorities. With advancements in technology, new functional ingredients are constantly being discovered and developed.
Common functional ingredients include those for caries prevention, plaque control, whitening, and desensitization, as well as herbal extracts and other bioactive compounds that may be added to the formulation, with each type of product potentially containing multiple functional ingredients.
12. Water for toothpaste
Water used in toothpaste production must be treated, with deionized water being the most common.
